The Ontogeny and Significance of Infants' Facial Expressions in the First 9 Months of Life.

Izard, Carroll E.; And Others

Developmental Psychology, v31 n6 p997-1013 Nov 1995

Four studies examined aspects of expressive behavior development in face-to-face mother-infant interactions. Found evidence of the morphological stability of discrete emotion expressions and that young infants respond differentially to positive conditions based on mother's interest and joy expressions and negative conditions based on sadness and anger expressions, supporting the differential emotions theory (DET) hypothesis. (HTH)